This kind of extensions load geometry just before the render starts. They´re useful to decrease the size of the scene file and even to create loaders for new file formats. This class is defined in geometryextension.h.
class CgeometryLoaderExtension : public CbaseExtension
{
public:
virtual bool loadMesh( Cmaxwell::Cobject& meshToLoad ) = 0;
virtual bool getBoundingBox( Cpoint& min, Cpoint& max )
{
return false;
};
virtual bool getProxyDisplayPoints( const dword& percent, const dword& maxPoints, dword& nPoints, float*& points )
{
return false;
};
virtual bool getProxyDisplayLines( const dword& percent, const dword& maxLines, dword& nPoints, float*& points, dword& nLines, dword*& pointsPerLine )
{
return false;
}
virtual bool getProxyDisplayFaces( const dword& percent, const dword& maxFaces, dword& nPoints, float*& points, dword& nFaces, dword*& faces )
{
return false;
}
};
The most important part of the extension functionality resides in loadMesh, which must be implemented. The rest are optional functions. getBoundingBox, if implemented, returns the maximum and minimum points of the geometry's bounding box, in local coordinates of the object. This function is called at the voxelization stage, just before starting to render.
One of the other three functions getProxyDisplay* should be implemented if the extension writer wants to draw an approximate proxy of the object in the Studio viewport. For example, the MaxwellGrass extension uses getProxyDisplayLines to draw some lines representing grass strands.
Cube creator
#include <math.h>
#include "extensionmanager.h"
#include "geometryextension.h"
#include "maxwell.h"
class CubeExampleExtension : public CgeometryLoaderExtension
{
DECLARE_EXTENSION_METHODS( "CubeExample", CubeExampleExtension, 1 )
Cmaxwell* pMaxwellLocal; //Handy to access the scene. If you want to use it, fill it in initializeForRendering
public:
CubeExampleExtension()
{
getExtensionData()->createDouble( "Cube size", 1.0, 0, 1000 );//Create parameter with Default value
}
~CubeExampleExtension()
{
}
bool initializeForRendering ( Cmaxwell* pMaxwell )
{
pMaxwellLocal = pMaxwell;
return true;
}
bool loadMesh( Cmaxwell::Cobject &cube )
{
//Get the extension parameter
getExtensionData()->getDouble( "Cube size", cubeSize );
//Create the mesh
cube.initializeMesh( 8, 6, 12, 1 );
//Add the vertices
Cpoint point;
point.assign( 0.0, 0.0, 0.0 );
cube.setVertex ( 0, 0, point );
point.assign( 0.0, 0.0, cubeSize );
cube.setVertex ( 1, 0, point );
point.assign( cubeSize, 0.0, cubeSize );
cube.setVertex ( 2, 0, point );
point.assign( cubeSize, 0.0, 0.0 );
cube.setVertex ( 3, 0, point );
point.assign( 0.0, cubeSize, 0.0 );
cube.setVertex ( 4, 0, point );
point.assign( 0.0, cubeSize, cubeSize );
cube.setVertex ( 5, 0, point );
point.assign( cubeSize, cubeSize, cubeSize );
cube.setVertex ( 6, 0, point );
point.assign( cubeSize, cubeSize, 0.0 );
cube.setVertex ( 7, 0, point );
//Set some normals
Cvector normal;
normal.assign( 1.0, 0.0, 0.0 );
cube.setNormal( 0, 0, normal );
normal.assign( -1.0, 0.0, 0.0 );
cube.setNormal( 1, 0, normal );
normal.assign( 0.0, 1.0, 0.0 );
cube.setNormal( 2, 0, normal );
normal.assign( 0.0, -1.0, 0.0 );
cube.setNormal( 3, 0, normal );
normal.assign( 0.0, 0.0, 1.0 );
cube.setNormal( 4, 0, normal );
normal.assign( 0.0, 0.0, -1.0 );
cube.setNormal( 5, 0, normal );
//Add triangles
cube.setTriangle ( 0, 0, 2, 1, 3, 3, 3 );
cube.setTriangle ( 1, 0, 3, 2, 3, 3, 3 );
cube.setTriangle ( 2, 4, 5, 6, 2, 2, 2 );
cube.setTriangle ( 3, 4, 6, 7, 2, 2, 2 );
cube.setTriangle ( 4, 2, 3, 7, 0, 0, 0 );
cube.setTriangle ( 5, 2, 7, 6, 0, 0, 0 );
cube.setTriangle ( 6, 0, 1, 5, 1, 1, 1 );
cube.setTriangle ( 7, 0, 5, 4, 1, 1, 1 );
cube.setTriangle ( 8, 1, 2, 6, 4, 4, 4 );
cube.setTriangle ( 9, 1, 6, 5, 4, 4, 4 );
cube.setTriangle ( 10, 0, 4, 7, 5, 5, 5 );
cube.setTriangle ( 11, 0, 7, 3, 5, 5, 5 );
//Generate some uvs
dword cchanIdx = 0;
dword daChan;
cube.addChannelUVW( daChan, cchanIdx );
Cbase projBase;
projBase.origin.assign( 0.5, 0.5, 0.5 );
projBase.xAxis.assign( 1.0, 0.0, 0.0 );
projBase.yAxis.assign( 0.0, 1.0, 0.0 );
projBase.zAxis.assign( 0.0, 0.0, 1.0 );
Cvector scale; scale.assign( 0.5, 0.5, 1.0 );
byte sux = cube.generateCubicUVW( cchanIdx, projBase );
return true;
}
bool getBoundingBox( Cvector &bmin, Cvector& bmax)
{
bmin.assign( -cubeSize, -cubeSize, -cubeSize );
bmax.assign( cubeSize, cubeSize, cubeSize );
return true;
}
};
EXPORT_GEOMETRY_LOADER_EXTENSION( CubeExampleExtension )